Originating OS Version

This DWORD should hold the kind of operating system in the high-order word and the version number of the operating system in the low-order word. Possible values for the operating system are:

Operating System	Value
32-Bit Windows (Win32)	0x0002
Macintosh	0x0001
16-Bit Windows (Win16)	0x0000

For Windows, the operating system version is the low-order word returned by the GetVersion function. On Windows, the following code would correctly set the version of the originating operating system:

#ifdef WIN32 
dwOSVer = (DWORD)MAKELONG( LOWORD(GetVersion()), 2 ) ; 
#else 
dwOSVer = (DWORD)MAKELONG( LOWORD(GetVersion()), 0 ) ; 
#endif